The usefulness and cost effectiveness of various non-invasive procedures performed on infants and children at their initial cardiac evaluation will be determined. Over a two year period, all patients seen for the first time in the pediatric cardiology clinics at Downstate Medical Center and Brookdale Hospital Medical Center, will be examined separately by three fully trained pediatric cardiologists. In addition, a chest X-ray, electrocardiogram, and M-mode echocardiogram will be obtained on each and the results will be compared with published standard norms for age. The pediatric cardiologists involved (Drs. A, B, and C) will evaluate the patients in the following manner: Dr. (A) history and physical only. Dr. (B) history, physical, chest X-ray, and electrocardiogram. Dr. (C) history, physical, and echocardiogram. Each examining physician will then independently arrive at a diagnosis from the available diagnostic data. The data will be statistically analyzed and conclusions can then be made as to the indications for performing the above non-invasive studies in these patients at their initial cardiac evaluation. It is hoped that the above study will provide valuable information to help physicians choose the most appropriate tests required to evaluate cardiac disease instead of ordering a battery of routine non-invasive studies.